JP6995913B2 - Topographic map output device, topographic map output method and program - Google Patents

Description

The present invention relates to a topographic map output device, a topographic map output method and a program.

Conventionally, a terrain analysis map expressing a three-dimensional shape of terrain on a plane has been created. Since it is impossible to express all the three-dimensional shapes of the terrain on a plane, the user of the terrain analysis map can use various terrain analysis maps such as stepped elevation map, slope map, and shadow map. , Select and use the terrain analysis map that expresses the shape of interest. In recent years, topographical analysis maps expressing fine topography such as fine unevenness on the surface of the earth and relative elevation values with respect to the surrounding topography have been used.

Patent Document 1 discloses a above-ground opening map and an underground opening map for expressing microtopography. Further, Patent Document 2 discloses a step-colored elevation map to which a LAC (Local Adaptive Contrast) process is applied in order to emphasize microtopography.

Japanese Unexamined Patent Publication No. 2004-53529 Japanese Unexamined Patent Publication No. 2008-242298

The methods described in Patent Documents 1 and 2 have a problem that the calculation load is large. Further, the methods described in Patent Documents 1 and 2 have a problem that it is difficult for the user to intuitively grasp the whole image of the terrain because only the undulations of the terrain of a predetermined scale are expressed. Therefore, there has been a demand for a method of generating a topographic map expressing the undulations of topography on a plurality of scales with a smaller computational load.

The present invention has been made to solve the above-mentioned problems, and is a topographic map output device and a topographic map output that can generate a topographic map expressing the undulations of topography on a plurality of scales with a smaller computational load. The purpose is to provide methods and programs.

The topographic map output device according to the present invention associates a plurality of unit areas corresponding to a plurality of geographical areas in which a target area is divided into a predetermined shape with an elevation value of the geographical area corresponding to each unit area. For each of a storage unit for storing, an acquisition unit for acquiring a plurality of different predetermined ranges of sizes and shapes composed of two or more unit areas, and a predetermined range having a plurality of acquired sizes and shapes. , The undulating feature amount of each unit region is calculated based on the relationship between the elevation value of each unit region and the elevation value of the unit region centered on each unit region and included in a predetermined range having each size and shape. It is characterized by having a calculation unit and an output unit that outputs a topographic map displaying each unit area in an embodiment calculated based on the undulation feature amount calculated for each of a predetermined range having a plurality of sizes and shapes.

In the topographic map output device according to the present invention, the output unit displays a topographic map in which each unit area is displayed in an embodiment based on the sum or product of the undulating feature amounts calculated for each of a predetermined range having a plurality of sizes and shapes. It is preferable to output.

In the topographic map output device according to the present invention, the calculation unit determines the undulation feature amount as the elevation value of each unit region and the elevation value of the unit region centered on each unit region and included in a predetermined range having each size and shape. It is preferable to calculate using the average value and the variance value of the values.

In the topographic map output device according to the present invention, the calculation unit calculates the inclination feature amount of each unit area based on the elevation value of each unit area, and the output unit further calculates each unit based on the calculated inclination feature amount. It is preferable to output a topographic map that displays the area.

In the topographic map output method according to the present invention, a plurality of unit areas corresponding to a plurality of geographical areas in which a target area is divided into a predetermined shape are associated with an elevation value of the geographical area corresponding to each unit area. Store and acquire a plurality of predetermined ranges having different sizes and shapes, each of which is composed of two or more unit areas, and for each of the acquired predetermined ranges having a plurality of sizes and shapes. A plurality of undulating feature quantities of a unit region are calculated based on the relationship between the elevation value of each unit region and the elevation value of a unit region centered on each unit region and included in a predetermined range having each size and shape. It is characterized by including outputting a topographic map displaying each unit area in an aspect based on the undulation feature amount calculated for each of the predetermined ranges having the size and shape of the above.

The program according to the present invention stores a plurality of unit areas corresponding to a plurality of geographical areas in which a target area is divided into a predetermined shape in association with an elevation value of the geographical area corresponding to each unit area. A computer program having a unit, which is composed of two or more unit areas, and obtains a plurality of predetermined ranges having different sizes and shapes.
For each of the acquired predetermined ranges having a plurality of sizes and shapes, the undulating feature amount of each unit region is set to the elevation value of each unit region and the predetermined range centered on each unit region and having each size. Calculated based on the relationship with the elevation value of the included unit area,
It is characterized in that a computer is made to output a topographic map displaying each unit area in an aspect based on the undulating feature amount calculated for each of the predetermined ranges having a plurality of sizes and shapes.

The topographic map output device, topographic map output method, and program according to the present invention make it possible to generate a topographic map expressing the undulations of topography on a plurality of scales with a smaller computational load.

It is a figure which shows an example of the schematic structure of the topographic map output device 1. It is a figure which shows an example of the data structure of the elevation value table T1. It is a flow chart which shows the 1st example of the flow of the topographic map output processing. It is a flow chart which shows an example of the flow of the undulation feature amount calculation process. It is a schematic diagram for demonstrating the undulation feature amount calculation process. It is a schematic diagram for demonstrating the undulation feature amount calculation process. It is a figure which shows an example of the step color elevation map. It is a figure which shows an example of the topographic map. It is a flow chart which shows the 2nd example of the flow of the topographic map output processing. It is a schematic diagram for demonstrating the undulation feature amount calculation process. It is a figure which shows an example of the topographic map which emphasized the undulation in a specific direction. It is a schematic diagram for demonstrating the undulation feature amount calculation process. It is a schematic diagram for demonstrating the undulation feature amount calculation process. It is a flow chart which shows the 3rd example of the flow of the topographic map output processing. It is a figure which shows an example of the topographic map. It is a flow chart which shows an example of the flow of the inclination feature amount calculation process. It is a schematic diagram for demonstrating the inclination feature amount calculation process. It is a figure which shows an example of the topographic map.

Hereinafter, various embodiments of the present invention will be described with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to those embodiments and extends to the inventions described in the claims and their equivalents.

(Rough configuration)
FIG. 1 is a diagram showing an example of a schematic configuration of a topographic map output device 1. The topographic map output device 1 has a storage unit 11, a communication unit 12, a display unit 13, an operation unit 14, and a processing unit 15.

The storage unit 11 is a device for storing a program or data, and includes, for example, a semiconductor memory device. The storage unit 11 stores an operating system program, a driver program, an application program, data, and the like used for processing by the processing unit 15. The program is a storage unit from a computer-readable and non-temporary portable storage medium such as a CD (Compact Disc) -ROM (Read Only Memory) or DVD (Digital Versatile Disc) -ROM using a known setup program or the like. It will be installed on 11.

The communication unit 12 is a device that enables the topographic map output device 1 to communicate with other devices, and includes a communication interface circuit. The communication interface circuit included in the communication unit 12 is a communication interface circuit such as a wired LAN (Local Area Network) or a wireless LAN. The communication unit 12 receives data from another device, supplies the data to the processing unit 15, and transmits the data supplied from the processing unit 15 to the other device.

The display unit 13 is a device for displaying an image, and includes, for example, a liquid crystal display or an organic EL (Electro-Luminescence) display. The display unit 13 displays an image based on the display data supplied from the processing unit 15.

The operation unit 14 is a device for receiving a user's input operation to the topographic map output device 1, and includes, for example, a keypad, a keyboard, or a mouse. The operation unit 14 may include a touch panel integrated with the display unit 13. The operation unit 14 generates a signal corresponding to the input operation of the user and supplies it to the processing unit 15.

The processing unit 15 is a device that comprehensively controls the operation of the topographic map output device 1, and includes one or a plurality of processors and peripheral circuits thereof. The processing unit 15 is, for example, a CPU (Central Processing Unit). The processing unit 15 may be a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or the like. The processing unit 15 has each configuration so that various processes of the topographic map output device 1 are executed in an appropriate procedure based on the programs stored in the storage unit 11 and the inputs from the communication unit 12 and the operation unit 14. It controls the operation and executes various processes.

The processing unit 15 includes a first acquisition unit 151, a second acquisition unit 152, a calculation unit 153, and an output unit 154 as its functional blocks. Each of these parts is a functional module realized by a program executed by the processing unit 15. Each of these parts may be mounted on the topographic map output device 1 as firmware. The first acquisition unit 151 and the second acquisition unit 152 are examples of acquisition units.

(data structure)
FIG. 2 is a diagram showing an example of the data structure of the elevation value table T1 stored in the storage unit 11. The elevation value table T1 associates a plurality of grids corresponding to a plurality of geographical areas in which a target area displayed by a topographic map is divided in a grid pattern with an elevation value of the geographical area corresponding to each grid. Each grid is arranged in a first direction and a second direction orthogonal to the first direction. The grid is an example of a unit area.

The elevation table T1 includes grid IDs, coordinates, geographical areas and elevation values. The grid ID is information for identifying each grid. The geographical area is information for identifying the geographical area corresponding to each grid, and is, for example, the latitude and longitude of the vertices of each of a plurality of geographical areas in which the target area is divided in a grid pattern. The geographical area may be the latitude and longitude of the diagonal end points of each geographical area, the latitude and longitude of the center point of each geographical area, and the like. The coordinates indicate the relative position of each grid with respect to the grid that serves as a reference for the position in the target area. The coordinates are represented, for example, by the number of grids corresponding to the distances in the first and second directions from the reference grid. The elevation value is an elevation value of each geographical area, and is determined by, for example, the minimum value of the elevation value of a point included in each geographical area. The elevation value may be determined by the average value, the median value, the mode value, or the like of the elevation values of the points included in each geographical area.

The data in the elevation value table T1 is generated based on, for example, three-dimensional point cloud data acquired by aerial laser survey or the like. Generally, the three-dimensional point cloud data acquired by aerial laser survey is data indicating the position of the reflection point of the laser light emitted from the flying aircraft, so that the ground surface, trees, buildings, etc. that can be the reflection point can be described. Shows the shape seen from above. Based on the distribution of each reflection point indicated by the 3D point cloud data, the reflection points of trees and erroneously detected reflection points are removed, and only the point cloud data corresponding to the reflection points on the ground surface is collected as 3D point cloud data. By extracting from, point cloud data indicating the terrain is generated. By dividing the generated point cloud data into groups according to the geographical area in which they are included, and setting the minimum elevation value of the reflection points included in each group as the elevation value of the corresponding geographical area. , The data of the elevation value table T1 is generated.

(Process flow)
FIG. 3 is a flow chart showing an example of a flow of topographic map output processing executed by the topographic map output device 1 in the first aspect of the present invention. The topographic map output processing is realized by the processing unit 15 executing the program stored in the storage unit 11 in cooperation with each configuration of the topographic map output device 1.

First, the first acquisition unit 151 acquires the size and shape of a window composed of two or more grids (S101). The first acquisition unit 151 acquires the size and shape of the window based on the operation of the operation unit 14 by the user. The first acquisition unit 151 may acquire the size and shape of the window by receiving it from another device via the communication unit 12. The first acquisition unit 151 may acquire the size and shape of a predetermined window stored in the storage unit 11 in advance. The shape of the window may be any shape, but is, for example, a rectangle. In this case, the first acquisition unit 151 acquires the number of grids in the first direction and the number of grids in the second direction as the size of the window. The number of grids in the first and second directions of the window is preferably an odd number so that the grid at the center of the window is uniquely determined. In the following, the number of grids in the first direction of the window may be expressed as 2c + 1, and the number of grids in the second direction may be expressed as 2r + 1 (both c and r are natural numbers). The window is an example of a predetermined range.

Subsequently, the calculation unit 153 executes an undulating feature amount calculation process for calculating the undulating feature amount of each grid (S102). The undulation feature amount is a value indicating how much each grid is undulating with respect to the grid around each grid. As the elevation value of a certain grid is larger than the elevation value of the surrounding grid, a larger value is calculated as the undulating feature amount of the grid. The undulation feature amount is calculated based on the relationship between the elevation value of each grid and the elevation value of the grid around each grid. For example, the undulation feature amount is calculated using the elevation value of each grid and the average value and the variance value of the elevation values of the grids around each grid. The details of the undulation feature amount calculation process will be described later.

Subsequently, the output unit 154 outputs a topographic map that displays each grid in an manner based on the calculated undulation feature amount (S103). The output unit 154 generates a topographic map displaying each grid with hue, saturation, lightness, etc. according to the calculated undulation feature amount. The output unit 154 outputs the generated topographic map by displaying it on the display unit 13. The output unit 154 may output the generated topographic map by transmitting it to another device via the communication unit 12.

FIG. 4 is a flow chart showing an example of the flow of the undulation feature amount calculation process.

First, the calculation unit 153 sets the grid at the initial position as the calculation target grid (S201). The grid at the initial position is, for example, a grid centered on such a grid and in which the corners of a window having the acquired size and shape touch the corners of a rectangular target area.

FIG. 5A is a schematic diagram for explaining S201. In the example shown in FIG. 5A, the target area, which is the area for outputting the topographic map, is divided into Nx geographical areas in the first direction D1 and Ny geographical areas in the second direction D2. That is, Nx × Ny grids corresponding to each geographical area are provided in the target area. Coordinates are set in each grid with reference to the grid located in the northwest direction (referred to as the upper left direction in FIG. 5A, the same shall apply hereinafter) among the grids belonging to the target area. That is, in each grid, a value of 0 or more and Nx-1 or less is set as the first direction coordinate, and a value of 0 or more and Ny-1 or less is set as the second direction coordinate.

In the example shown in FIG. 5A, the calculation unit 153 sets the grid G at the initial position as the calculation target grid. The grid G is a grid centered on the grid G so that the northwest end of the window W having the acquired size and shape coincides with the northwest end of the target area. As will be described later, the calculation unit 153 calculates the undulating feature amount of each calculation target grid by using a window centered on each calculation target grid while moving the calculation target grid to the first direction D1 by one grid. do. When the grid at the folding position becomes the calculation target grid, the calculation unit 153 moves the calculation target grid from the initial position to the second direction D2 by one grid, and moves the coordinates in the first direction so as to be equal to the initial position. Let me. The grid at the folded position is a grid such that the end portion of the window centered on the grid in the first direction coincides with the end portion of the target area in the first direction. The calculation unit 153 calculates the undulating feature amount of each calculation target grid while moving the calculation target grid in the first direction again. By repeating such processing, the calculation unit 153 calculates the undulating feature amount of each grid.

Returning to FIG. 4, the calculation unit 153 calculates and stores the sum of the elevation values and the sum of squares of the grids included in the grid group obtained by dividing the window in the first direction (S202). The grid group that divides the window in the first direction is composed of grids that are continuous in the second direction. The grid group is an example of a unit area group.

FIG. 5B is a schematic diagram for explaining S202. As shown in FIG. 5B, the calculation unit 153 sets a plurality of grid group GGs in which the window W is divided in the first direction. In the example shown in FIG. 5B, since the second direction coordinates of the grid included in the window W are in the range of 0 or more and 4 or less, the second direction coordinates of the grid included in each grid group are also 0 or more and 4 or less. A plurality of grid group GGs are set so as to be a range. The calculation unit 153 calculates the sum of elevation values and the sum of squares of the grids included in each set grid group. In the following, the sum of elevation values and the sum of squares included in a grid group composed of grids whose first direction coordinates are x may be described as Sum (x) and SqSum (x), respectively.

Returning to FIG. 4, the calculation unit 153 calculates the undulating feature amount of the calculation target grid (S203). The undulation feature amount is calculated based on the relationship between the elevation value of the grid to be calculated and the elevation value of the grid included in the window. For example, the undulation feature amount is calculated using the elevation value of the grid to be calculated and the average value and the variance value of the elevation values of the grid included in the window. In this case, the calculation unit 153 calculates and stores the average value and the variance value in the window based on the sum and the sum of squares in the grid group. The calculation unit 153 calculates and stores the mean value μ and the variance value V by the following formulas. Here, x is the first direction coordinate of the calculation target grid.

Subsequently, the calculation unit 153 calculates the undulating feature amount R of the calculation target grid by using the elevation value H of the calculation target grid and the mean value μ and the variance value V of the elevation values of the grid included in the window. Calculated by the formula.

Subsequently, the calculation unit 153 moves the calculation target grid in the first direction (S204). The calculation unit 153 moves the calculation target grid in the first direction by one grid. That is, the calculation unit 153 sets a grid adjacent to the first direction of the calculation target grid as a new calculation target grid. The calculation unit 153 sets a window centered on the moved calculation target grid.

Subsequently, the calculation unit 153 divides the first window centered on the first grid on which the undulation feature amount was calculated immediately before and the second window centered on the calculation target grid in the first direction. The sum of elevation values and the sum of squares of the grids included in the above are calculated (S205).

FIG. 6A is a schematic diagram for explaining S205. The calculation unit 153 calculates the sum of elevation values and the sum of squares in the grid group obtained by dividing the first window W1 and the second window W2 in the first direction. The first window W1 is a window centered on the grid G1 on which the undulating feature amount is calculated immediately before, and the second window W2 is a window centered on the calculation target grid G2. Here, among the grid groups obtained by dividing the second window W2 in the first direction, the sum of elevation values and the sum of squares in the grid group included in the first window W1 have already been calculated in S202 and the like. Therefore, the calculation unit 153 calculates only the sum of elevation values and the sum of squares in the first grid group GG1 composed of the grids not included in the first window W1 and included in the second window.

Returning to FIG. 4, the calculation unit 153 calculates the undulating feature amount of the calculation target grid (S206). The calculation unit 153 calculates the average value and the variance value in the second window. For example, the calculation unit 153 includes the average value of the elevation values of the grid included in the second window, the average value of the elevation values of the grid included in the first window, the average value of the elevation values of the grid included in the first window, and the second window. Calculated based on the elevation values of the grid not included in and the elevation values of the grid not included in the first window and included in the second window. Further, the calculation unit 153 includes the distribution value of the elevation value of the grid included in the second window, the distribution value of the elevation value of the grid included in the first window, and the distribution value of the elevation value of the grid included in the first window, and is included in the second window. Calculated based on the elevation values of the grid not included in and the elevation values of the grid not included in the first window and included in the second window. The calculation unit 153 calculates the undulating feature amount of the calculation target grid by using the elevation value of the calculation target grid and the average value and the variance value of the elevation values of the grid included in the second window.

As shown in FIG. 6A, a part of the grid included in the first window W1 and a part of the grid included in the second window W2 overlap. Since the average value in the window is based on the sum of the elevation values of each grid included in the window, the number of operations is reduced by using the average value in the first window W1 when calculating the average value in the second window W2. Will be done. Similarly, since the variance value in the window is based on the sum of squares of the elevation values of each grid contained in the window, the variance value in the first window W1 can be used when obtaining the variance value in the second window W2. The number of operations is reduced.

Using the average value μ'and the variance value V'in the first window W1 and the calculated sum and square sum, the calculation unit 153 calculates the mean value μ and the variance value V in the second window W2 by the following equations. calculate.

Returning to FIG. 4, the calculation unit 153 determines whether or not the calculation target grid is a grid at the folding position (S207). The calculation unit 153 determines whether or not the maximum value of the first direction coordinates of the grid included in the window centered on the calculation target grid is equal to Nx-1, so that the calculation target grid is a grid at the folding position. Determine if it is present or not. When it is determined that the calculation target grid is not the grid at the folding position (S207-No), the calculation unit 153 advances the process to S204.

When it is determined that the calculation target grid is the grid at the folding position (S207-Yes), the calculation unit 153 determines whether or not the calculation target grid is the grid at the end position. (S208). The grid at the end position is a grid that is point-symmetrical to the grid at the initial position with respect to the center of the target area. That is, the grid at the end position is a grid in which the diagonal of the angle that was in contact with the corner of the target area at the initial position of the window centered on the grid is in contact with the corner of the target area. The calculation unit 153 determines whether or not the calculation target grid is the grid at the end position by determining whether or not the maximum value of the second direction coordinates of the grid included in the window is equal to Ny-1. When it is determined that the calculation target grid is the grid at the end position (S208-Yes), the calculation unit 153 ends the undulation feature amount calculation process.

When it is determined that the calculation target grid is not the grid at the end position (S208-No), the calculation unit 153 moves the calculation target grid in the second direction (S209). The calculation unit 153 moves the calculation target grid in the second direction by one grid and moves the coordinates in the first direction so as to be equal to the initial position. The calculation unit 153 sets a window centered on the moved calculation target grid.

Subsequently, the calculation unit 153 calculates and stores the sum of the elevation values and the sum of squares of the grids included in the grid group obtained by dividing the window in the first direction (S210). For example, the calculation unit 153 converts the sum of elevation values and the sum of squares of the grids included in the second grid group obtained by dividing the third window centered on the calculation target grid into the first grid group. Calculated using the sum of elevations and the sum of squares of the included grid. The first grid group is a grid group obtained by dividing the first window centered on the first grid, which is adjacent to the calculation target grid in the second direction and whose undulation feature amount has already been calculated, in the first direction. .. The calculation unit 153 includes the sum of elevation values and the sum of squares of the grids included in the second grid group, the sum of the elevation values and the sum of squares of the grids included in the first grid group, and the sum of squares in the first grid group. It is calculated and stored based on the elevation values of the grids that are not included in the second grid group and the elevation values of the grids that are not included in the first grid group and are included in the second grid group.

FIG. 6B is a schematic diagram for explaining S210. As shown in FIG. 6B, a part of the grid included in the first grid group GG1 in which the sum of elevation values and the sum of squares is calculated, and the moved window are divided in the first direction. It overlaps with a part of the grid included in the grid group GG2 of 2. Therefore, by using the sum of elevation values and the sum of squares of the first grid group GG1 when calculating the sum of elevation values and the sum of squares of the second grid group GG2, the number of operations is reduced.

続いて、算出部１５３は、処理をＳ２０３に進める。 The calculation unit 153 is a third window W3 centered on a calculation target grid G3 adjacent to the first grid G1 for which the undulation feature amount has already been calculated, which is composed of grids continuous in the second direction. Is calculated in the sum of elevation values and the sum of squares in each second grid group GG2 divided in the first direction. The calculation unit 153 uses the sum of the elevation values Sum (x) and the squared sum SqSum (x) of each second grid group GG2 as the elevation values of the first grid group GG1 corresponding to each second grid group GG2. Sum'(x) and sum of squares SqSum'(x) and the elevations of the grids included in the first grid group GG1 corresponding to each second grid group GG2 and not included in each second grid group GG2. Calculated by the following formula based on the value H1 and the elevation value H2 of the grid not included in the first grid group GG1 corresponding to each second grid group GG2 and included in each second grid group GG2. And remember.

Subsequently, the calculation unit 153 advances the process to S203.

FIG. 7 is a diagram showing an example of a step color elevation map in which each grid is displayed with a hue, saturation, or lightness that changes stepwise according to the altitude value, and FIG. 8 is a diagram showing a step color shown in FIG. 7. It is a figure which shows an example of the topographic map generated by performing the topographic map output processing in the 1st side surface based on the data of the elevation value table T1 corresponding to the elevation map. 8 (a) and 8 (b) are topographic maps generated using windows having different sizes, and the size of the window in FIG. 8 (a) is the window in FIG. 8 (b). Is smaller than the size of.

In FIG. 7, a region having a large elevation value (for example, a region corresponding to a ridge) is displayed brightly, and a region having a small elevation value (for example, a region corresponding to a valley) is displayed darkly. Further, in FIG. 7, for example, the inside of the region corresponding to the ridge is displayed with substantially uniform brightness. That is, although the step-colored elevation map shown in FIG. 7 expresses the undulations of large-scale terrain, it cannot clearly express the undulations due to micro-topography.

The step color elevation map is expressed by displaying the entire distribution width of the elevation value of the target area with a limited range of hue, saturation, lightness, and the like. When the target area is wide, the area where the difference in elevation value is relatively small is displayed with similar hue, saturation, lightness, etc., and the change becomes unclear. Therefore, there is a possibility that the microtopography is not sufficiently expressed in the stepped elevation map.

On the other hand, in FIG. 8A, for example, the inside of the region corresponding to the ridge is also displayed with different brightness, and the undulations due to the microtopography are sufficiently expressed. The undulating feature amount shown in FIG. 8A is based on the difference between the elevation value of each grid and the average value of the elevation value of the window centered on each grid (that is, the deviation of the elevation value). Therefore, even when the distribution width of the elevation values of the target region is large, the regions where the difference in elevation values is relatively small are displayed with different hues, saturations, brightnesses, etc., and the microtopography is clearly expressed.

The undulation feature amount is the deviation of the elevation value of each grid normalized by the standard deviation. Therefore, even if the target area includes a region where the terrain has a large undulation due to microtopography (that is, a region where the standard deviation of the elevation value is large) and a region where the terrain has a small undulation (that is, a region where the standard deviation is small). The microtopography of the area with small undulations is fully expressed.

In addition, since the distribution width of the elevation value differs depending on the target area in the step-colored elevation map, the creator of the topographic map responds to the distribution width so that the undulations of the terrain of the desired scale can be sufficiently expressed. It was necessary to decide the display method. On the other hand, the undulation feature is a normalization of the deviation of the elevation value with the standard deviation, so when the elevation value follows a normal distribution, the undulation feature of about 99% of the grid is in the range of -3 or more and 3 or less. It is distributed in. Therefore, the same display method can be used even if the distribution widths of the elevation values are different, and the load on the creator of the topographic map to determine the display method is reduced.

In FIG. 8B, the region having a large elevation value is displayed brightly, the region having a small elevation value is displayed darkly, and the microtopography represented in FIG. 8A is also represented. That is, as the size of the window increases, the undulations of large-scale terrain that are not clearly expressed in FIG. 8A are clearly expressed. In this way, by displaying each grid in an manner based on the undulation feature amount, the details of the microtopography in the target area are expressed when the size of the window is reduced, and when the size of the window is increased, the target area is displayed. The outline of the terrain in.

As described above, the topographic map output device 1 uses the elevation value of each grid and the average value and the variance value of the elevation value of the grid included in the window centered on each grid to determine the undulating feature amount of each grid. calculate. This makes it possible for the topographic map output device 1 to generate a topographic map expressing microtopography with a small calculation load.

That is, since the above-ground opening and the underground opening, which are indexes for expressing microtopography, are calculated by angles, calculations such as trigonometric functions are required for the calculation. Therefore, the method of using the above-ground opening and the underground opening for each grid has a problem that the calculation load is large. Further, the LAC process emphasizes the undulations of the microtopography in consideration of the elevation value of the entire target area. Therefore, in the method of applying the LAC processing to the existing topographic map such as the step color elevation map, when the target area is large, the average value of the elevation values of the entire target area and the elevation value after the application of the LAC processing are used. There is a problem that the calculation load for calculating the distribution width becomes large.

On the other hand, the topographic map output device 1 calculates the undulating feature amount of each grid by using the average value and the variance value of the grid included in the window centered on each grid. That is, it is not necessary to consider the undulations of the entire target area in order to calculate the undulation features. Therefore, the topographic map output device 1 makes it possible to generate a topographic map expressing microtopography with a small calculation load.

Further, the topographic map output device 1 sets the mean value and the variance value in the second window centered on the second grid adjacent to the first grid in the first direction, and the mean value and the variance value in the first window. Is calculated using. This makes it possible for the topographic map output device 1 to calculate the mean value and the variance value by a small load operation of addition and subtraction once, respectively, regardless of the size of the window.

Further, the topographic map output device 1 sets the average value and the dispersion value in the grid group obtained by dividing the third window centering on the third grid adjacent to the first grid in the second direction, and the first grid. It is calculated using the mean value and the variance value in the grid group in which the center window is divided. As a result, the topographic map output device 1 can calculate the sum of elevation values and the sum of squares of the grids included in the grid group by performing a small load operation of addition and subtraction once, respectively, regardless of the size of the window. And.

In the above description, in S202 and S205, the calculation unit 153 calculated the sum of the elevation values and the sum of squares of the grid group obtained by dividing the window in the first direction, respectively, but the present invention is not limited to this. In S202, the calculation unit 153 may calculate the sum of elevation values and the sum of squares of all grid groups composed of grids corresponding to the range of the second direction coordinates of the grid included in the window. In this case, in S210 as well, the calculation unit 153 calculates the sum of elevation values and the sum of squares of all grid groups composed of grids corresponding to the range of the second direction coordinates of the grid included in the window. May be good.

FIG. 9 is a flow chart showing an example of a flow of topographic map output processing executed by the topographic map output device 1 in the second aspect of the present invention. The topographic map output processing is realized by the processing unit 15 executing the program stored in the storage unit 11 in cooperation with each configuration of the topographic map output device 1.

First, the first acquisition unit 151 acquires the size and shape of a window composed of two or more grids (S301).

Subsequently, the second acquisition unit 152 acquires the direction of inclination emphasized by the undulating feature amount of each grid (S302). The second acquisition unit 152 acquires the direction of the tilt to be emphasized based on the operation of the operation unit 14 by the user. The direction of the slope to be emphasized is the direction in which the undulating feature amount is calculated to be larger when the altitude value becomes larger toward such a direction than when it is not. The second acquisition unit 152 may acquire the emphasized tilt direction by receiving it from another device via the communication unit 12. The second acquisition unit 152 may acquire the direction of inclination stored in the storage unit 11 in advance.

Subsequently, the calculation unit 153 executes the undulation feature amount calculation process (S303). The details of the undulation feature amount calculation process will be described later.

Subsequently, the output unit 154 outputs a topographic map that displays each grid in an manner based on the calculated undulation feature amount (S304).

The undulating feature amount calculation process in the second aspect differs from the undulating feature amount calculation process in the first aspect in the processes of S203 and S206.

FIG. 10 is a schematic diagram for explaining the processing of S203 and S206 in the second aspect. In S203 and S206, the calculation unit 153 sets the undulating feature amount of the calculation target grid into a window centered on the calculation target grid and the elevation value of the grid corresponding to the position of the calculation target grid and the direction acquired in S302. Calculated based on the relationship with the elevation values of the included grid. The grid corresponding to the position of the calculation target grid and the acquired direction is a grid located in the direction opposite to the acquired direction when viewed from the calculation target grid.

For example, the calculation unit 153 specifies a grid located in the opposite direction of the direction D when viewed from the calculation target grid G among the eight grids surrounding the calculation target grid G. The calculation unit 153 acquires the elevation value of the specified grid as the elevation value H'of the grid corresponding to the position and the direction D of the calculation target grid. The calculation unit 153 calculates the undulating feature amount R of the calculation target grid based on the relationship between the acquired elevation value H'and the elevation value of the window centered on the calculation target grid G. For example, the calculation unit 153 sets the undulating feature amount R of the calculation target grid as the acquired elevation value H', the average value μ of the elevation values of the grid included in the window centered on the calculation target grid G, and the variance value V. Is calculated by the following formula.

In the second aspect, the undulation feature is calculated using the elevation value of the grid located in the direction opposite to the direction D of the slope to be emphasized, instead of the elevation value of each grid. For example, when the direction D is the northwest direction, the undulating feature amount is calculated using the elevation value of the grid located in the southeast direction of each grid. In the region where the elevation value decreases toward the northwest direction, the undulation feature is calculated to be larger than when the elevation value of each grid itself is used by using the elevation value of the grid located in the southeast direction of each grid. Will be done. On the other hand, in the region where the elevation value decreases toward the southeast direction, by using the elevation value of the grid located in the southeast direction of each grid, the undulating feature amount becomes smaller than when the elevation value of each grid is used. It is calculated. Therefore, by displaying the region with a large amount of undulating features brightly, a topographic map such as a shadow map projected from the region side with a small elevation value is generated. In this way, by calculating the undulation feature amount using the elevation value of the grid located in the direction opposite to the direction D, the inclination in a specific direction is emphasized, and the terrain is in a manner that is easy for the user to intuitively understand. The undulations of are expressed.

FIG. 11 is a diagram showing an example of a topographic map output by executing the topographic map output process on the second side surface. In FIG. 11, the undulating feature amount of the region where the elevation value decreases toward the northwest direction is calculated to be large, and the region is brightly colored. Therefore, in FIG. 11, the undulations of the terrain are expressed in a manner that is easy for the user to intuitively understand, as if it were a shadow map projected from the northwest direction. Further, in FIG. 11, the microtopography is clearly expressed as in FIG. 9A.

As described above, the topographic map output device 1 averages the elevation values of the grid corresponding to the position of each grid and the direction of the slope to be emphasized and the elevation values of the grid included in the window centered on each grid. The undulation feature of each grid is calculated using the value and the variance value. This makes it possible for the topographic map output device 1 to generate a topographic map that emphasizes the inclination in a specific direction with a small calculation load.

The undulating feature amount calculation process in the second aspect is not limited to the above-mentioned example. Another example of the undulating feature amount calculation process in the second aspect differs from the undulating feature amount calculation process in the first aspect in the processes of S203 and S206.

FIG. 12 is a schematic diagram for explaining the processing of S203 and S206. In S203 and S206, the calculation unit 153 relates the elevation value of the calculation target grid to the elevation value of the grid included in the window centered on the grid corresponding to the position of the calculation target grid and the direction acquired in S302. Based on, the undulating feature amount of the calculation target grid is calculated. The calculation unit 153 sets a window W'centered on the grid G'located in the direction D when viewed from the calculation target grid among the eight grids surrounding the calculation target grid G. The calculation unit 153 calculates the undulation feature amount using the elevation value of the calculation target grid G and the average value and the variance value in the window W'.

In this case, the undulating feature amount is calculated by using the average value in the window centered on the grid located in the direction D as viewed from each grid instead of each grid. For example, when the direction D is the northwest direction, the undulating feature amount is calculated using the average value in the window centered on the grid located in the northwest direction of each grid. Generally, in the region where the elevation value decreases toward the northwest direction, the average value in the window centered on the grid located in the northwest direction of each grid is smaller than the average value in the window centered on each grid. Therefore, by using the window centered on the grid located in the northwest direction of each grid, the undulating feature amount is calculated to be larger than in the case of using the window centered on each grid. In this way, by calculating the undulation feature amount using the average value of the window centered on the grid located in the direction D, the inclination in a specific direction is emphasized and the user can easily understand it intuitively. The undulations of the terrain are expressed.

The example of the grid corresponding to the position of the calculation target grid and the acquired direction in S203 and S206 is not limited to the above-mentioned example. For example, the calculation unit 153 may specify a plurality of grids corresponding to the position of the calculation target grid and the acquired direction D. In this case, in S203 and S206, the calculation unit 153 sets the undulating feature amount of each grid as the weighted sum of the elevation values of the plurality of grids corresponding to the position of each grid and the acquired direction, and is centered on each grid. Calculated based on the relationship with the elevation value of the grid contained in the window with the acquired size.

FIG. 13A is a schematic diagram for explaining an outline of the processing of S203 and S206. In the example shown in FIG. 13A, the north-northwest direction is acquired as the direction D. In this case, the calculation unit 153 specifies two grids, the grid G1 and the grid G2, as grids located in the opposite direction of the direction D when viewed from the calculation target grid G. The calculation unit 153 calculates the weighted sum of the elevation values of the specified grid G1 and grid G2. The weight of the elevation value is set so that the grid located closer to the opposite direction of the direction D when viewed from the calculation target grid, the greater the weight. In the example shown in FIG. 13A, since the grid G1 and the grid G2 are located in the south direction and the southeast direction, respectively, when viewed from the calculation target grid G, it can be said that they are close to each other in the opposite direction of the direction D. Therefore, the calculation unit 153 calculates the arithmetic mean of the elevation value of the grid G1 and the elevation value of the grid G2 as a weighted sum. This makes it possible for the topographic map output device 1 to generate a topographic map that emphasizes undulations in any direction with a small computational load.

Further, in S302, the second acquisition unit 152 may further acquire the degree of inclination emphasized in the undulation feature amount. In this case, in S203 and S205, the calculation unit 153 uses the undulating feature amount of each grid as the weighted sum of the elevation values of the plurality of grids corresponding to the position of each grid and the acquired direction and inclination, and each grid. It is calculated based on the relationship with the elevation value of the grid contained in the window centered on and having the acquired size.

FIG. 13B is a schematic diagram for explaining an outline of the processing of S203 and S206. In the example shown in FIG. 13B, the northwest direction is acquired as the direction D. Further, 30 degrees is acquired as the inclination degree E. In this case, the calculation unit 153 specifies the grid G1 as a grid located in the direction opposite to the direction D when viewed from the calculation target grid G. The calculation unit 153 calculates a weighted sum of the elevation value of the grid G to be calculated and the elevation value of the specified grid G1 by weighting according to the degree of inclination. The relationship between the degree of inclination and the weight is set in advance so that the smaller the acquired degree of inclination, the larger the weight of the calculation target grid G, and the larger the degree of inclination, the larger the weight of the specified grid G1.

As described in the second aspect, by calculating the undulation feature amount using the elevation value of the grid located in a specific direction when viewed from each grid, the inclination in a specific direction is emphasized in the topographic map. This corresponds to the fact that when the virtual light source is set in the direction of a specific azimuth and elevation angle in the shading diagram, the inclination of the specific direction and the degree of inclination is emphasized. On the other hand, as described in the first aspect, when the undulation feature amount is calculated using the elevation value of each grid, the inclination in a specific direction is not emphasized in the topographic map. This corresponds to the fact that the tilt in a particular direction is not emphasized when the hypothetical light source is set to an elevation angle of 90 degrees (ie, upwards) in the shading diagram. Therefore, by calculating the undulation feature using the weighted sum of the elevation value of each grid and the elevation value of the grid located in a specific direction when viewed from each grid, the elevation angle of the virtual light source becomes the specific elevation angle. It is possible to express a state between the elevation angle of 90 degrees.

The example of specifying the elevation values of a plurality of grids is not limited to the above. For example, the calculation unit 153 may specify three or more grids from the eight grids surrounding the calculation target grid. Further, when the calculation unit 153 acquires an inclination degree larger than the reference inclination degree as the inclination degree of the undulations to be emphasized, the calculation unit 153 may specify a grid different from the eight grids surrounding the calculation target grid.

FIG. 14 is a flow chart showing an example of a flow of topographic map output processing executed by the topographic map output device 1 in the third aspect of the present invention. The topographic map output processing is realized by the processing unit 15 executing the program stored in the storage unit 11 in cooperation with each configuration of the topographic map output device 1.

First, the first acquisition unit 151 acquires the sizes and shapes of a plurality of different windows composed of two or more grids (S401).

Subsequently, the calculation unit 153 selects the size and shape of one window from the acquired sizes and shapes of the plurality of windows (S402).

Subsequently, the calculation unit 153 executes the undulation feature amount calculation process using the size and shape of the selected window (S403).

Subsequently, the calculation unit 153 determines whether or not the undulating feature amount has been calculated for all the acquired window sizes and shapes (S404). When it is determined that the undulating feature amount has not been calculated for all the acquired window sizes and shapes (S404-No), the calculation unit 153 returns to S402 to determine the size and shape of the acquired plurality of windows. From among them, select the size and shape of one window that has not been selected yet.

When it is determined that the undulating features have been calculated for all the acquired window sizes and shapes (S404-Yes), the output unit 154 has calculated the undulating features for each of the windows having a plurality of sizes and shapes. A topographic map displaying each grid in a quantity-based manner is output (S405). The output unit 154 outputs, for example, a topographic map that displays each grid based on a value obtained by adding the undulation features calculated for each window.

FIG. 15 is a diagram showing an example of a topographic map output by executing the topographic map output process on the third side surface. In FIG. 15, the area corresponding to the ridge is displayed brightly, and the microtopography inside the area corresponding to the ridge is also sufficiently expressed. That is, since the undulation feature amount is calculated based on the relationship between the elevation value of each grid and the elevation value of the grid contained in the window centered on each grid, the undulation of the scale according to the size of the window is emphasized. Will be done. In FIG. 15, since windows having a plurality of different sizes are used, it is possible to express the undulations of terrain of different scales.

As described above, the topographic map output device 1 displays a topographic map centered on each grid and displays each grid according to a plurality of undulating feature quantities calculated using a plurality of windows having different sizes. Output. This makes it possible for the topographic map output device 1 to generate a topographic map expressing the undulations of the terrain at a plurality of scales with a small computational load.

In S405, the output unit 154 adds the undulating feature amount calculated for each window, but the present invention is not limited to such an example. For example, the output unit 154 may calculate the weighted sum of the undulating features. This makes it possible to arbitrarily change the scale of terrain undulations to be emphasized.

Further, in the above description, in the second aspect and the third aspect, the undulation feature amount calculated by using the elevation value of the grid and the average value and the variance value of the elevation value of the grid included in the window is used. However, it is not limited to such an example. As the undulating feature amount based on the relationship between the elevation value of the grid and the elevation value of the grid included in the window, the tilting feature amount calculated by the tilting feature amount calculation process described later may be used. In this case, in S303 and S403, the calculation unit 153 executes the inclination feature amount calculation process instead of the undulation feature amount calculation process.

FIG. 16 is a flow chart showing an example of the flow of the inclined feature amount calculation process.

First, the calculation unit 153 calculates the approximate slope of each grid (S601). The approximate slope is an approximate value of the slope of each grid. The calculation unit 153 calculates the approximate slope of each grid based on the elevation values of each grid and the elevation values of eight adjacent grids adjacent to each grid.

FIG. 17 is a schematic diagram for explaining the processing of S601. As shown in FIGS. 17A and 17B, the vertical component Nz of the unit normal vector N with respect to the inclined surface in contact with the calculation target grid G1 and the adjacent grid G2 corresponds to the inclination of the inclined surface. Take different values. Therefore, the vertical component Nz can be used as the degree of inclination of the calculation target grid G1 with respect to the adjacent grid G2.

したがって、算出対象グリッドＧ１の隣接グリッドＧ２に対する傾斜度Ｎｚは以下の式により表される。

Here, the angle θ formed by the unit normal vector N and the vertical direction is expressed by the following equation using the difference ΔH between the elevation value of the calculation target grid G1 and the elevation value of the adjacent grid G2.

Therefore, the inclination Nz of the calculation target grid G1 with respect to the adjacent grid G2 is expressed by the following equation.

ここで、Ｅ［｜ΔＨ｜］は、算出対象グリッドＧ１の標高値と隣接グリッドの標高値との差の絶対値を、８個の隣接グリッドについて平均した値である。このようにして、算出部１５３は、１回の平方根の演算で算出対象グリッドＧ１の近似傾斜度Ｎｚ’を算出する。 The slope of the calculation target grid G1 can be calculated by calculating the slope Nz for each of the eight adjacent grids surrounding the calculation target grid G1, but in this case, it is necessary to calculate the square root eight times. There is. In order to reduce the calculation load, the calculation unit 153 calculates the approximate slope Nz'of the grid to be calculated by the following formula.

Here, E [| ΔH |] is a value obtained by averaging the absolute value of the difference between the elevation value of the calculation target grid G1 and the elevation value of the adjacent grid for eight adjacent grids. In this way, the calculation unit 153 calculates the approximate inclination degree Nz'of the calculation target grid G1 by one calculation of the square root.

Subsequently, the calculation unit 153 sets the grid at the initial position as the calculation target grid (S602). The calculation unit 153 sets a window centered on the calculation target grid.

Subsequently, the calculation unit 153 calculates the sum of the approximate slopes of the grid group in which the window is divided in the first direction, which is composed of the grids continuous in the second direction (S603).

Subsequently, the calculation unit 153 calculates the tilt feature amount of the calculation target grid (S604). The slope feature is the average value of the approximate slope of the grid contained in the window.

Subsequently, the calculation unit 153 moves the calculation target grid in the first direction (S605). The calculation unit 153 moves the calculation target grid in the first direction by one grid. The calculation unit 153 sets a window centered on the moved calculation target grid.

Subsequently, the calculation unit 153 divides the first window centered on the first grid on which the tilt feature amount was calculated immediately before and the second window centered on the calculation target grid in the first direction. The sum of the approximate slopes of the grids included in is calculated (S606).

Subsequently, the calculation unit 153 calculates the tilt feature amount of the calculation target grid (S607). The calculation unit 153 is a grid composed of a grid that is included in the first window and is not included in the second window centered on the calculation target grid in the inclination feature amount of the grid for which the inclination feature amount was calculated immediately before. By adding the sum of the approximate slopes of the group and reducing the sum of the approximate slopes of the grids composed of the grids not included in the first window and included in the second window, the tilt features of the grid to be calculated are calculated. Is calculated.

Subsequently, the calculation unit 153 determines whether or not the calculation target grid is a grid at the folding position (S608). When it is determined that the calculation target grid is not the grid at the folding position (S608-No), the calculation unit 153 advances the process to S605.

When it is determined that the calculation target grid is the grid at the folding position (S608-Yes), the calculation unit 153 determines whether or not the calculation target grid is the grid at the end position. (S609). When it is determined that the calculation target grid is the grid at the end position (S609-Yes), the calculation unit 153 ends the process.

When it is determined that the calculation target grid is not the grid at the end position (S609-No), the calculation unit 153 moves the calculation target grid in the second direction (S610). The calculation unit 153 moves the calculation target grid in the second direction by one grid and moves the coordinates in the first direction so as to be equal to the initial position. The calculation unit 153 sets a window centered on the moved calculation target grid.

Subsequently, the calculation unit 153 calculates the sum of the approximate slopes of the grid group in which the window is divided in the first direction, which is composed of the grids continuous in the second direction (S611). The calculation unit 153 approximates the second grid group in which the third window centered on the third grid adjacent to the first grid on which the tilt feature amount is calculated is divided in the first direction. Calculate the sum of the slopes. The calculation unit 153 is included in the first grid group and is included in the sum of the approximate slopes of the first grid group obtained by dividing the first window centered on the first grid in the first direction. By subtracting the approximate slope of the grid not included in the group and adding the approximate slope of the grid not included in the first grid group and included in the second grid group, the approximate slope of the second grid group is added. Calculate the sum of degrees. Subsequently, the calculation unit 153 advances the processing to S604.

In this way, by using the tilt feature amount as the feature amount based on the relationship between the elevation value of the grid and the elevation value of the grid included in the window, the topographic map output device 1 performs a small calculation of the topographic map expressing the slope. It is possible to generate with a load. In the second side surface and the third side surface, the topographic map output device 1 may use the degree of inclination, the opening degree, or the like as the undulation feature amount.

In the third aspect, the topographic map output device 1 outputs a topographic map that displays each grid based on the undulation feature amount calculated for each of the windows having a plurality of sizes. The topographic maps to be made are not limited to such examples. For example, the topographic map output device 1 may output a topographic map that displays each grid based on the tilt feature amount and the undulation feature amount calculated for each of the windows having a plurality of sizes. In this case, the topographic map output device 1 displays each grid by hue, saturation, brightness, etc. according to the value obtained by adding the tilt feature amount and the undulation feature amount calculated for each of the windows having a plurality of sizes. Output the topographic map to be used.

FIG. 18 is a diagram showing an example of a topographic map displaying each grid based on the inclined features and the undulating features calculated for each of the windows having a plurality of sizes. In FIG. 18, the undulations and microtopography of large-scale terrain are sufficiently represented as in FIG. Further, in FIG. 18, by further using the tilt feature amount, the undulations of the terrain are displayed in a manner in which the three-dimensional effect is intuitively easy to understand.

As described above, the topographic map output device 1 displays each grid according to the tilt feature amount and the plurality of undulating feature amounts calculated by using a plurality of windows having different sizes centered on each grid. Output topographic map. As a result, the topographic map output device 1 can generate a topographic map that expresses a wide-area undulating shape and a local undulating shape in a manner in which the three-dimensional effect is intuitively easy to understand with a small computational load. And.

In the third aspect, the topographic map output device 1 outputs a topographic map that displays each grid in an manner based on the inclined feature amount and the undulating feature amount calculated for each of the windows having a plurality of sizes. However, it is not limited to such an example. The topographic map output device 1 may further output a topographic map that displays each grid based on the altitude value. For example, the topographic map output device 1 multiplies and synthesizes a topographic map based on an elevation value and a topographic map based on an undulating feature amount.

Additive synthesis of the topographic map based on the slope features and the topographic map based on the undulation features is performed based on the following equation. Here, I1 is the luminance of the pixel corresponding to each grid of the topographic map based on the inclined feature amount, I2 is the luminance of the pixel corresponding to each grid of the topographic map based on the undulating feature amount, and I3 is It is the brightness of the pixel corresponding to each grid of the topographic map that has been added and synthesized. α is the weight of additive synthesis, and takes a value of 0 or more and 1 or less.

なお、各画素が複数のチャネル（例えば、ＲＧＢの３チャネル）を有する場合は、各チャネルについて以上の式が適用される。 The multiplication composition of the additively synthesized topographic map and the step-colored elevation map based on the elevation value is performed based on the following equation. Here, I4 is the luminance of the pixel corresponding to each grid of the step color elevation map, and I5 is the luminance of the pixel corresponding to each grid of the multiplied topographic map. Imax is the maximum value of the luminance of each pixel, and is 255 when the color depth is 8 bits. β is a weight of multiplication and composition, and takes a value of 0 or more and 1 or less.

When each pixel has a plurality of channels (for example, three channels of RGB), the above equation is applied to each channel.

As a result, the topographic map output device 1 makes it possible to display the height of the terrain in a manner that is intuitively easy for the user to understand. Further, the topographic map output device 1 may use the inclination degree instead of the inclination feature amount. The composition of the inclined feature amount, the undulating feature amount, and the elevation value is not limited to the above example. For example, the inclined feature amount, the undulating feature amount, and the elevation value may be sequentially added and combined, or may be sequentially multiplied and combined. Further, after multiplying and synthesizing the undulating feature amount and the elevation value, the result and the inclined feature amount may be added and combined.

In the above description, a grid corresponding to a plurality of geographical areas in which the target area is divided in a grid pattern is used, but the present invention is not limited to such an example. For example, a unit area corresponding to a plurality of geographical areas in which the target area is divided into hexagons may be used. Further, the target area may be partitioned into any predetermined shape.

It will be appreciated by those skilled in the art that various changes, substitutions and modifications can be made to this without departing from the spirit and scope of the invention. For example, the processes of the above-mentioned parts may be executed in different orders as appropriate within the scope of the present invention. Further, the above-described embodiments and modifications may be carried out in appropriate combinations within the scope of the present invention.

1 Topographic map output device 11 Storage unit 151 First acquisition unit 152 Second acquisition unit 153 Calculation unit 154 Output unit

Claims (6)

A storage unit that stores a plurality of unit areas corresponding to a plurality of geographical areas in which a target area is divided into a predetermined shape, and an elevation value of the geographical area corresponding to each unit area in association with each other.
An acquisition unit that acquires a plurality of predetermined ranges of sizes and shapes having at least different sizes, which are composed of two or more unit areas.
For each of the plurality of predetermined ranges having at least different sizes, the undulating feature amount of each unit region is set to the elevation value of each unit region and the predetermined range centered on each unit region and having each size and shape. A calculation unit that calculates the slope features of each unit area while calculating based on the relationship with the elevation value of the included unit area.
An output unit that outputs a topographic map that displays each unit area in an embodiment based on the calculated undulating features for each of the plurality of predetermined ranges and the calculated inclined features .
Have,
The calculation unit calculates the approximate slope of each unit region using the average value of the absolute values of the differences between the elevation values of each unit region and the elevation values of a plurality of adjacent unit regions surrounding the unit region, and the calculation is performed. The tilt feature amount of each unit region is calculated based on the approximate slope of each unit region.
A topographic map output device characterized by this. The calculation unit averages the approximate inclination of the unit region included in the predetermined range centering on the unit region for each unit region to calculate the inclination feature amount of the unit region, and at that time, the first The inclined feature amount of the unit region included in the second predetermined range centered on the second unit region adjacent to the first direction of the unit region of the above is the first predetermined amount centered on the first unit region. The tilt feature amount of the unit region included in the range, the approximate slope of the unit region included in the first predetermined range and not included in the second predetermined range, and included in the first predetermined range. It is calculated based on the approximate inclination of the unit region included in the second predetermined range.
The topographic map output device according to claim 1. The output unit outputs a topographic map that displays each unit area in a mode based on the sum or product of the undulating features calculated for each of the plurality of predetermined ranges.
The topographic map output device according to claim 1 or 2 . The calculation unit sets the undulating feature amount as the elevation value of each unit region and the average value and the dispersion value of the elevation values of the unit regions centered on each unit region and included in a predetermined range having each size and shape. Calculated using
The topographic map output device according to any one of claims 1-3. A plurality of unit areas corresponding to a plurality of geographical areas in which the target area is divided into a predetermined shape are stored in association with each other and the elevation value of the geographical area corresponding to each unit area is stored.
Obtain multiple predetermined ranges of sizes and shapes , each consisting of two or more unit areas and having at least different sizes.
For each of the plurality of predetermined ranges having at least different sizes, the undulating feature amount of each unit region is set to the elevation value of each unit region and the predetermined range centered on each unit region and having each size and shape. Calculate based on the relationship with the elevation value of the included unit area, and calculate the tilt feature of each unit area .
It includes outputting a topographic map displaying each unit area in an embodiment based on the calculated undulating feature amount for each of the plurality of predetermined ranges and the calculated inclined feature amount .
In the above calculation, the approximate slope of each unit region is calculated using the average value of the absolute values of the differences between the elevation values of each unit region and the elevation values of a plurality of adjacent unit regions surrounding the unit region. The slope feature amount of each unit area is calculated based on the calculated approximate slope of each unit area.
A topographic map output method characterized by this. A computer program having a storage unit that stores a plurality of unit areas corresponding to a plurality of geographical areas in which a target area is divided into a predetermined shape and an elevation value of the geographical area corresponding to each unit area in association with each other. There,
Obtain multiple predetermined ranges of sizes and shapes , each consisting of two or more unit areas and having at least different sizes.
For each of the plurality of predetermined ranges having at least different sizes, the undulating feature amount of each unit region is set to the elevation value of each unit region and the predetermined range centered on each unit region and having each size and shape . Calculate based on the relationship with the elevation value of the included unit area, and calculate the tilt feature of each unit area .
The computer is made to output a topographic map displaying each unit area in a mode based on the calculated undulating feature amount for each of the plurality of predetermined ranges and the calculated inclined feature amount .
In the above calculation, the approximate slope of each unit region is calculated using the average value of the absolute values of the differences between the elevation values of each unit region and the elevation values of a plurality of adjacent unit regions surrounding the unit region. The slope feature amount of each unit area is calculated based on the calculated approximate slope of each unit area.
A program characterized by that.

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